Based on Noctua"s compact NH-U9 series and fitted with the award-winning NF-B9 fan and NT-H1 thermal compound, the NH-U9DX forms a complete premium quality package that provides excellent quiet cooling performance for 4U Xeon workstations and servers. The new SecuFirm2TM mounting system for socket 771 is highly convenient and makes the NH-U9DX a tailor-made drop-in replacement for standard Intel coolers. To make your Xeon systems quieter has never been so easy!